Session B9: Phase Transitions, Dynamics, and Excitations

11:15 AM–2:03 PM, Monday, March 13, 2006
Baltimore Convention Center Room: 301

Sponsoring Unit: DCMP
Chair: Alberto Pimpinelli, Université Blaise Pascal

Abstract ID: BAPS.2006.MAR.B9.1

Abstract: B9.00001 : Competing periodicities in fractionally filled quasi-1D bands

11:15 AM–11:27 AM

Preview Abstract MathJax On | Off   Abstract  


  P.C. Snijders
    (Kavli Institute of Nanoscience)

  S. Rogge
    (Kavli Institute of Nanoscience, Delft, The Netherlands)

  H.H. Weitering
    (University of Tennessee, Knoxville, and Oak Ridge National Laboratory, USA)

We present a variable temperature Scanning Tunneling Microscopy and Spectroscopy (STM and STS) study of the Si(553)-Au atomic chain reconstruction. This quasi one-dimensional (1D) system undergoes at least two charge density wave (CDW) transitions at low temperature, which can be attributed to electronic instabilities in the fractionally-filled 1D bands of the high-symmetry phase. Upon cooling, Si(553)-Au first undergoes a single-band Peierls distortion, resulting in period doubling along the imaged chains. This Peierls state is ultimately overcome by a competing tripleperiod CDW, which in turn is accompanied by a $\times $2 periodicity in between the chains. These locked-in periodicities indicate small charge transfer between the nearly half-filled and quarter-filled 1D bands. The mobility of atomic scale dislocations in the $\times $3 CDW state indicates the possibility of manipulating phase solitons carrying a (spin,charge) of (1/2,$\pm $e/3) or (0,$\pm $2e/3).

To cite this abstract, use the following reference: